Microphone assembly with self-contained power supply



April 1, 1969 E. PLESS ETAL" MICROPHONE ASSEMBLY WITH SELF-CONTAINED POWER SUPPLY Sheet Filed April 16, 1965 E rnsf Pless F ig.2

Rudolf Gb'rike INVENTORS.

Attorney p 1969 Q E. PLESS ETAL 3,436,482

MICROPHONE ASSEMBLY WITH SELF'CONTAINED POWER SUPPLY Filed April 16, 1965 Sheet Z of 3 Ernsf Pless Rudolf Go'rike INVENTORS.

Attorn y April 1, 1969 E. PLESS ETAL. 3,436,482

MICROPHONE ASSEMBLY WITH SELF-CONTAINED POWER SUPPLY Filed April 16, 1965 I Sheet 3 of 5 I z l f G k u o ori e F I9. 4 INVENTORS.

Attorn y United States Patent 3,436,482 MICROPHONE ASSEMBLY WITH SELF- CONTAENED POWER SUPPLY Ernst Pless and Rudolf Giirike, Vienna, Austria, assignors to Alkustische und Kino-Gerate G.m.b.H., Vienna, Austria, a corporation of Austria Filed Apr. 16, 1965, Ser. No. 448,893 Claims priority, application Austria, Apr. 16, 1964, A 3,333/64 Int. Cl. Htl4m 1/00 U.S. Cl. 179-1 ABSTRACT OF THE DISCLOSURE 3 Claims Our present invention relates to an electroacoustic transducer comprising at least one microphone together with a stand therefor.

In commonly assigned application Ser. No. 319,833, filed Oct. 29, 1963 by Rudolf Gorike, now Patent No. 3,336,441, there has been disclosed a transducer of this type wherein a microphone is supported on a stand which accommodates associated circuit elements in a tubular column thereof and/ or in a housing supported on top of that column. In a specific embodiment disclosed in the prior application, a reverberation unit including an elongated coil spring and two electromagnetic inductance coils separated thereby is received within the column itself, the inductance coils being inserted in a feedback circuit of an amplifier within the microphone housing by a plugand-jack connection releasably joining the housing to the top of the column. The prior application also suggests the positioning of batteries serving as a power supply for the microphone, in the housing thereof.

The general object of our present invention is to provide an electroacoustic transducer of this type in which the circuit elements associated wit-h the microphone, to the extent that they are supported by the microphone stand, are so located as to afford a more flexible weight distribution whereby the center of gravity of the stand is lowered to improve its stability.

Another object of this invention is to provide means in such transducer for enabling the aforementioned circuit elements, or some of them, to be controlled by an operator (e.g. a speaker facing the microphone) at a location remote from the microphone stand.

According to a feature of our invention, the microphone stand comprises a base and an upright support rising therefrom, the microphone being fixedly or removably positioned at the top of this support while at least part of the associated circuit elements, e.g. the power supply and/or an amplifier, are disposed in the base and are connected to the microphone by a suitable transmission line. Advantagtously, the upright is a tubular column of the type disclosed in the prior application, serving again to accommodate a reverberation unit or echo device of the character described above.

According to another feature of our invention, a manual control device is connected with the stand by way of ice a flexible elongated operating element, such as an electric cable ora mechanical linkage, which advantageously is detachably joined to the control device and/ or the microphone housing; if the flexible connector is provided with mating terminations at opposite ends, it may be removed when not required so that complementary coupling means on the control device and on the microphone housing may be interfitted for a direct mounting of the device on the housing.

The above and other objects, features and advantages of our invention will become more readily apparent from the following detailed description, reference being made to the accompanying drawing in which:

FIG. 1 is a perspective view of an electroacoustic transducer representing a first embodiment;

FIG. 2 shows a modified transducer representing a second embodiment; and

FIGS. 3 and 4 are diagrammatic representations of the embodiments shown in FIGS. 1 and 2, respectively.

The assembly illustrated in FIG. 1 comprises a microphone 15 supported on a stand which includes a base 2 with legs 1 and a tubular column 3 rising from that base. A rod 17 is vertically positioned alongside column 3 and is slidable relatively thereto with the aid of brackets 18, 19 to vary the elevation of the microphone 15 carried at the top of this rod; a locking lever 20 serves to hold the rod 17 with its microphone 15 in a selected position.

Column 3 contains an echo device including an elongated reverberation spring; as illustrated in FIG. 3, this device also includes an input coil 21 and an output coil 22 at the bottom and at the top, respectively, of spring 16. A sleeve 4, manually slidable along the upper end of column 3, controls the operation of the units 16, 21, 22 which is connected, in a manner well known per se, in a feedback circuit of a second stage 121) (FIG. 3) of a two-stage amplifier 12 disposed within base 2. Also accommodated within that base is a power supply 13 which in this particular instance is shown to comprise a line transformer 13a and a rectifier 13b (see again FIG. 3). A cable 8, adapted to be plugged into a wall socket or other outlet carrying alternating current, is connected across the primary winding of transformer 13a and extends from the bottom of the base 2. Another cable 9, having its conductors connected across the output of amplifier 12, extends outwardly of base 2 for plug-in connection to a loudspeaker, transmitting station or other suitable load.

Still another flexible cable 10 leads from the microphone 15 to the base 2 where it is connected across the input of the first or preamplifier stage 12a (FIG. 3) of amplifier 12. The lenth of cable 10 is, of course, so chosen as to allow for a maximum elevation of microphone 15.

At 6 we have shown a manual control device with a handle 14 adapted to be manipulated by an operator standing at some distance from the microphone 15. Although the device 6 is representative of any remote-control means for adjusting the operating circuit of microphone L5, e.g. by controlling the amplifier 12 thereof in the manner described hereinafter with reference to FIGS. 3 and 4, we have illustrated in FIGS- 1 and 2 only a connection between this device and the slider 4 which controls the reverberation unit 16, 21, 22. More particularly, the connection shown in FIGS. 1 and 3 is constituted by a mechanical linkage 7 which, in this specific embodiment, is illustrated as a Bowden wire connected between handle 14 and sleeve 4; this wire enters the column 3 through a cap 5 thereof. Thus, either the speaker himself or some other person holding the device 6- may vary the echo effect without having to stand so close to the column 3 as is necessary for a direct shifting of slider 4.

FIG. 2 shows a manual control device 6' connected by way of multiconductor cable 7' (see also FIG. 4) to the column 3 of a stand, otherwise similar to that of FIG. 1, which has a microphone directly supported on top of this column. The connection between microphone 15' and column 3 may be releasable and may include a coupling of the plug-an-jack type as disclosed in the aboveidentified Gorike application. Similarly, the cable 7 also forms a detachable linkage between column 3' and control device 6, being provided for this purpose with a male termination 7a and a complementary female termination 71) respectively mating with jacks 3a on column 3' and and terminal pins 6a on control device 6'. It will be apparent that the pins 6a may be plugged directly into the jacks 3a if the cable 7' is omitted. The number of pins and jacks, of course, corresponds to the number of conductors of cable 7' which have been illustrated in FIG. 4.

The individual controls of the device 6 have been shown to include an on-off switch 140 and sliders 14a, 14b of two potentiometers which, as illustrated in FIG. 4, are connected to respective control electrodes of amplifier stages 12a and 12!). As shown in FIG. 4, these amplifier stages are disposed in the instant embodiment within the column 3' itself, above the echo device 16, 21', 22' which is substantially identical with that of the preceding embodiment. The power supply for the operating circuit of microphone 15', again located in base 2', is here shown as a battery 13', thus eliminating the need for the input cable 8 of FIGS. 1 and 3. The output cable has been illustrated at 9'.

It will thus be apparent that we have disclosed a system in which remote control of the output of an electroacoustic transducer is atforded by means of a mechanical linkage, such as a flexible shaft or a Bowden wire, or an electrical connector, such as a multiconductor cable, extending between a microphone stand and a control device adapted to be held in the hand of a user. Naturally, the same principle can be adapted for the remote control of a plurality of transducers from a single command post or control panel. Also, several microphones could be mounted on one stand, e.g. one at a fixed elevation on the column itself (as shown in FIGS. 2 and 4) and one at an adjustable level on an extension arm thereof (as shown in FIG. 1). These and other modifications, readily apparent to persons skilled in the art, are intended to be embraced within the spirit and scope of our invention as defined in the appended claims.

We claim:

1. An electroacoustic transducer comprising at least one microphone; a stand for said microphone and circuit means received in said stand, said circuit means including a power supply, a reverberation unit and an amplifier for said microphone, said stand including a base and a tubular column rising from said base, said microphone being mounted at the top of said column, at least said power supply being disposed in said base, said reverberation unit including a coil spring extending longitudinally within said column, said emplifier having an input and an output inductively coupled to respective extremities of said spring; and control means movable along said column and mechanically connected with one of said extremities for varying the echo effect of said reverberation unit.

2. A transducer as defined in claim 1, further comprising manual operating means for said control means disposed externally of said stand and a flexible elongated connection between said stand and said operating means.

3. A transducer as defined in claim 1 wherein said amplifier is disposed in said base along with said power supply.

References Cited UNITED STATES PATENTS 1,887,637 11/1932 Hansen 179-l50 XR 2,969,436 l/l961 Kilyk 179-448 3,007,014 10/1961 Bentman 179-148 FOREIGN PATENTS 1,373,546 8/1964 France.

1,167,551 4/1964 Germany.

OTHER REFERENCES Michels: A Simulated Echo Chamber, Radio & TV News, November 1951.

KATHLEEN H. CLAFFY, Primary Examiner.

R. P. TAYLOR, Assistant Examiner.

US. Cl. X.R. 

